looks like the engine will kill the trunk area. not as bad as them hayabusa/smart conversions where the engine looks like it's in the passenger seat. it's better than cramming a couple of huge sub-woofers in there (totally useless). i've sorta outgrown my "need for speed" after i sold my '70 firebird 29 years ago, now i like to kick back a little and enjoy the scenery, I-90 through southern minnesota is quite nice, at 75mph in a geo metro it's almost terrifying, it would be pleasant at 55mph in a smart.
looks quite interesting, good luck with your little project!